Ruthan Lewis

Mars surface tunnel element concept

When the first human visitors on Mars prepare to return to Earth, they will have to comply with stringent planetary protection requirements. Apollo Program experience warns that opening an EVA hatch directly to the surface will bring dust into the ascent vehicle. To prevent inadvertent return of potential Martian contaminants to Earth, careful consideration must be given to the way in which crew ingress their Mars Ascent Vehicle (MAV). For architectures involving more than one surface element - such as an ascent vehicle and a pressurized rover or surface habitat - a retractable tunnel that eliminates extravehicular activity (EVA) ingress is an attractive solution. Beyond addressing the immediate MAV access issue, a reusable tunnel may be useful for other surface applications, such as rover to habitat transfer, once its primary mission is complete. A National Aeronautics and Space Administration (NASA) team is studying the optimal balance between surface tunnel functionality, mass, and stowed volume as part of the Evolvable Mars Campaign (EMC). The study team began by identifying the minimum set of functional requirements needed for the tunnel to perform its primary mission, as this would presumably be the simplest design, with the lowest mass and volume. This Minimum Functional Tunnel then becomes a baseline against which various tunnel design concepts and potential alternatives can be traded, and aids in assessing the mass penalty of increased functionality. Preliminary analysis indicates that the mass of a single-mission tunnel is about 237 kg, not including mass growth allowance.

Neutral Buoyancy Methodology for Studying Satellite Servicing EVA Crewmember Interfaces

Current economic constraints indicate the need for incorporating the satellite servicing philosophy of commonality within the design of spacecraft subsystems. This philosophy is essential for conserving resources including hardware/software development and implementation costs, on-orbit and ground-based manpower, crew training/testing time, and documentation. In addition, spacecraft subsystem commonality may be coupled with standardization of operational procedures, and test and verification techniques for spacecraft design. Several spacecraft have adapted this practice, including Hubble Space Telescope, Space Station Freedom, and the Explorer Platform. As these and other programs continue and if effective crew interfaces and procedures are clearly and consistently defined, crew retraining for similar spacecraft subsystems will lessen, and procurement efforts will diminish. A relatively high fidelity zero-gravity simulation using water immersion is available to establish crew interfaces economically. The flexibility and utility of this space simulation medium for planning and assisting on-orbit operations was exemplified by astronaut evaluations of potential extravehicular activity electrical connectors. The testing was conducted at a National Aeronautics and Space Administration underwater neutral buoyancy training facility.

Application of Site Analysis to Enhance Lunar and Mars Expeditionary Base Design

Revitalization of NASA’s lunar robotic and human exploration program is underway. Data from previous exploration missions is being reexamined, interpolated, and extrapolated to near term and far term needs for development of human outposts. Within the development process, site analysis will use this data and propose new data required to establish the infrastructure design for which environmental effects are accounted, facility functions and arrangement are optimized, safety and health risks are minimized, and science return is maximized. The content and application of site analysis to lunar outpost and base design and utilization will be discussed.

All Up Analog Simulations: Why they are Essential for Planning Long Duration Human Missions to the Moon and Mars

Long duration human expeditionary missions to the Moon and Mars, such as those currently proposed, will require extensive use of many systems to support exploration and maintain health and safety of the crew. Interaction with these systems for the purpose of control, monitoring and operation will be a full time job whether the crewmembers are in the field (EVA – Extravehicular Activity) or in the habitat (IVA – Intravehicular Activity). Understanding how to coordinate all of the functions and activities that must occur at an expeditionary outpost suggests recreating the same functions and activities at an earth analog site. The analog site includes the habitat/s, all habitat support systems, internal and external, rovers, balloons, science equipment, remote camps, etc., that would be required for an actual mission. This approach differs from analog studies that have been performed to date, as they tend to involve testing of one piece of equipment or one operational modality at a time. Facilities in extreme environments will also be used as precedents for the expeditionary analog. The facilities investigated may include polar outposts (South Pole Station), undersea habitats (Conshelf, Sealab, Tektite), space habitats (Skylab, Salyut, Mir, ISS) and planetary surface bases (the Apollo “J” mission landing sites – Apollo 15, 16 and 17). Study of these facilities may reveal systems and procedures that may be beneficial (or should not be duplicated) at the planetary Earth analog site. The author’s experience in design of two (2) analog training facilities (The Antarctic High Station, 1993 and the Flashline Mars Arctic Research Station, 1998 to 2000) will be used to explain the nature of the test facility and the integration of all systems. An analysis of the various systems and the relationships between them and the human users will also serve to demonstrate the possible difficulties inherent in this undertaking and how mission success may be achieved with All-Up analog simulation.

Site Planning and Design for First Expeditionary Lunar and Mars Missions

This study proposes that planetary protection issues, especially forward and back contamination, mandate thoughtful site operations and organization planning for human expeditions to Mars or to other planets. Planetary protection, while primarily concerned with contamination, also relates to prevention of physical damage to the site and is not merely an aesthetic issue. It involves preservation of visible geomorphologic features necessary for identification of structures and processes that may lead to water and/or life bearing or fossiliferous strata, as well as providing geological information regarding the natural history of the planet. The study shall explain how careful planning, site operations and organization may increase the efficiency of the outpost, as additions are completed and new components installed. What this will mean for the explorer/astronaut is everything that is needed to support the outpost will have a definitive place before arrival. In previous terrestrial polar operations, experienced operations and logistics personnel locate things as they see fit. This usually follows certain logic, but does not adhere to an organizational rigor that can be applied by a design professional and is instrumental to the safe and effective operation of human settlements. Placement of equipment within and outside habitats may also adhere to certain constraints relative to adjacencies of certain types of systems. Existing codes used in terrestrial design and construction will be reviewed relative to Mars site development and recommended as part of a comprehensive planetary surface site design guideline. Development of a comprehensive Mars specific code is an eventual goal. The study will also address site operations and organization planning that extends to exploration and construction activities in the hinterland. Universal, internationally mandated procedures must be established for how any explorers will initially identify traverse paths and move from their habitat to logistics areas and to pre-designated scientific exploration zones.